Dragline excavator



Feb. 15,, 1944. w BAGER 2,341,838

DRAGLINE EXCAVATOR Filed Sept. 29, 1941 s Sheets-Sheet 1 INVENTOR.

BY 96 M f ATTORNEYS Feb. 15, 1944. w, LBAGER 2,341,838

DRAGLINE EXCAVATOR Filed Sept. 29, 1941 3 Sheets-Sheet 2 I INVENTOR.

BY 247 U ATTORNEY-5' Feb. 15, 1944. w. M. BAGER DRAGLINE EXCAVATOR Filed Sept. 29, 1941 3 Sheets-Sheet 3 'mn/n INVE OR.

ATTORNEY-5 Patented Feb. 15, 1944 DRAGLINE EXCAVATOR William M. Eager, Milwaukee, Wis., assignor to Bueyrus-Erie Company,

South Milwaukee, Wis.,

a corporation of Delaware Application September 29, 1941, Serial No. 412,795

6 Claims.

My invention relates'to new and useful improvements in dragline excavatorsof the general type developed under the Page patent,.N o. 758, 380. 1

Such machines ar characterized by the fact that a forked hoist line supports the digging bucket behind the center of gravity thereof, and a forked hauling line is attached to the two front edges of the bucket. A stabilizing line extends, 10

aim to attain an archless bucket, minimum interference by the hauling and stabilizing lines with the material being excavated, a lighter bucket, and smaller and hence more flexible ropes.

Another principal object of myinvention is to provide a design which will permit the use of smaller drums, smaller fairleads and lighter driving machinery for the hauling means.

In addition to my principal. objects, above stated, I have worked out a number of novel and useful details, which will be readily evident as the description progresses.-

My invention consists in the novel parts and in the combination and arrangement thereof, which, are defined in the appended claims,;and of which a number of embodiments are exemplified in the accompanying drawings, which are hereinafter particularly described and explained.

Throughout the description the same reference number is applied to the same member or to similar members.

Figure l is a side elevation of a dragline excavator embodying my invention. The bucket is shown in two positions (onein full lines, the other dotted) of its cycle.

Figure 2 is a plan View of the same.

Figure 3 is an enlarged plan view of my bucket.

Figure 4 is an enlarged side elevation of my bucket.

Figures 5 and 6 are schematic plan views of a dragline excavator showing my invention with alternative arrangements of the drag lines when the machine is digging on a slope.

Referring to Figures 1 and 2, We see that H is the main base of an excavator. Pivoted at the front end thereof is a boom I2, suspended from such a way as to increasethe steadiness therean A-frame E3 on the base II, by tackle l4, actuable by a boom-hoist winch-drum IS. The power means for actuating this winch-drum, and the other winch-drums hereinafter mentioned, is conventional, and hence need not be shown.

From a double winch-drum l6on the base I I, extend two hoist lines l1, over twin sheaves l8 at the point of the boomlZ, to bucket l9.

From a second winch-drum 20 on the base ll, extend, two hauling lines 2|, through, twin fairleads 22 at the foot of the boom l2, to bucket l9. This drum may be a single drum equipped with an equalizer, as explained below, or a double drum; equipped with a differential drive.

There are also twin stabilizing lines 23, which will'be -more particularly described hereinafter.

Turning'now tov Figures 3 and 4, for the details of 'my bucket, we see that each hoist line I! consists of rope in itspart remote from the bucket, l9, and of chain in its part adjacent the bucket; but this is merely preferable.

Similarly each'hauling line 2| consists of rope in its part remote from the bucket I9, and of chain in its part adjacent the bucket; but this is merely preferable.

Each hoist line I! is attached to one side of the bucket I9, behind the transverse axis of the center of gravity thereof. Each hauling line 2! is attached to the front of one side of the bucket l9, by a clevis z habove and forward of the digging ,teeth 25.

Each stabilizing line 23 extends from onehauling line 2|, around a sheave 26, carried by the corresponding hoist line H, to an anchorage 2'! i at the upper-front corner of the corresponding side of the bucket.

Due to the; wide spacing of sheaves I8 at the point of the boom l2, and to the wide spacing of fairleads 22 at the foot of the boom, and to the twinning of each of the three lines (hoisting ll,

hauling 2i and stabilizing 23), we have a bucket which will be steady in the work, which has no arch to interfere with filling and which has hauling lines which are easy-to handle and require i lighter smaller drums, fairleads and driving machinery, and yet which operates exactly as the conventional Page bucket.

Referring now to Figure 5, an example of the way in which my invention enables steadying the bucket, would be when digging along a side slope. If the main base of the machine be swung so that the outer end of the boom is above a point higher up the bank than the level to be excavated, the tension in the hoist ropes will hold the bucket to the bank, but, if the parallel hauling lines are of equal length (as shown in dotted lines in Figure 5) the orientation of the bucket will be such that it will tend to dig down hill in a line parallel with the boom.

There are a number of ways in which my improved design can be adopted to overcome such a tendency and at the same time insure maintenance of equal tension on the hauling or drag ropes.

If a double winch with a differential drive be used, unequal tension in the parallel drag lines (shown dotted in Figure 5) will cause the drum to pay out on the line adjacent the bank and to take in on the outer line, with the result that the bucket will automatically be oriented to 'dig in the direction of the machine, rather than in a line parallel with the boom. In cases, where the difference in tension is likely to be very great, as, for example, when one side of the bucket encounters a large rock and all of the hauling load is thrown on one of the two drag lines, it is advisable to connect the drag ropes to the apex 28 of a forked drag chain 29 which has branches attached to the sides of the bucket l9. (See full lines in Figure 5.) Then, even though the whole load: is thrown on one chainlwhich is built to withstand such a strain), that load is transmitted substantially equally to the two drum equalizing drag lines which may, therefore, be lighter than the drag chains, to permit the use of lighter drums and driving machinery.

If a single drum winch is used with equalizing means at theouter ends of the drag ropes adjacent the bucket, the advantages of light twin drag ropes are likewise attained. This equalizing means may consist of an equalizing bar 30 connected at its midpoint 3| to the apex of the forked drag chains 29 and at its ends to the hauling lines, as shown in Figure 6.

Accordingly we see that my use of twin drag line ropes with means to equalize tension therein makes it possible to use a pair of drag ropes with a'smaller drum, smaller fairleads, smaller driving machinery and less power than in the conventional drag line which uses a single large drag rope,

Having now described and illustrated several forms of my invention, I wish it to be understood that my invention is not to be limited to the specific forms or arrangements of parts herein described and shown, except as specifically covered by my claims.

I claim: I

1. In a dragline excavator, the combination of: a drag bucket; a support for the bucket, pivoted thereto behind the center of gravity thereof, and adapted to exert an upward pull thereon; two

hauling lines adapted to exert a substantially horizontal pull on said bucket; means operatively connecting these lines together and to the bucket at widely laterally spaced points; a base; two laterally spaced fairleads on the base, for the two hauling lines; a winch on the base, having drum means for the two hauling lines; said winch being adapted to vary the relative effective length of the two hauling lines.

2. In a dragline excavator, the combination of: a drag bucket; a support for the bucket, pivoted thereto behind the center of gravity thereof, and adapted to exert an upward pull thereon; two hauling lines adapted to exert a substantially horizontal pullon said bucket at widely laterally spaced points; a base; two laterally spaced fairleads on the base, for the two hauling lines; a

which on the base, having drum means for the two hauling Iines; and means, associated with the two hauling lines, to equalize tension in the two hauling lines, including means operatively connecting t'nese lines together and. to the bucket.

3. In a-dragline excavator, the combination of; a drag bucket; a support for the bucket, pivoted thereto behind the center of gravity thereof, and adapted to exert an upward pull thereon; a winch; 'and two hauling lines, extending from'the winch to the bucket at laterally spaced points, and attached to each other in advance of the bucket.

4. In a dragline excavator, the combination of: a drag bucket; hoist means attached to the bucket behind the center'of gravity thereof; and' haulingmean comprising: an equalizing beam, tension means connecting the midpoint of the equalizing beam'and the forward end of the bucket, I and two hauling lines attached to the equalizing beam at laterally spaced points. 5. In a dragline excavaton 'the combination of a drag bucket; a support for the bucket, pivoted thereto behind the center of gravity thereof, and adapted to exert an upward pull thereon; and hauling means comprising: an equalizing beam, tension means connecting the equalizing beam and the forward end of the bucket, and two hauling lines attached to the equalizing beam at laterally spaced points. I

6. In a dragline excavator, the combination of: a drag bucket; hoist means attached to the bucket'behind the center of gravity thereof; and

hauling means comprising: two hauling lines,

sion means connecting the forward end of' the 

